the temperature of the particular field
which is drained, the general effect of the drainage of wet lands upon
the climate of the neighborhood has often been noticed. In the paper
already cited, emanating from the Board of Health, we find the
following remarks, which are in accordance with all observation in
districts where under-drainage has been generally practiced:

"Every one must have remarked, on passing from a district with a
retentive soil to one of an open porous nature--respectively
characterized as cold and warm soils--that, often, whilst the air
on the retentive soil is cold and raw, that on the drier soil is
comparatively warm and genial. The same effect which is here caused
naturally, may be produced artificially, by providing for the
perfect escape of superfluous water by drainage, so as to leave
less to cool down the air by evaporation. The reason of this
difference is two-fold. In the first place, much heat is saved, as
much heat being required for the vaporization of water, as would
elevate the temperature of more than three million times its bulk
of air one degree. It follows, therefore, that for every inch in
depth of water carried off by drains, which must otherwise
evaporate, as much heat is saved per acre as would elevate eleven
thousand million cubic feet of air one degree in temperature. But
that is not all. Not only is the temperature of the air reduced,
but its dew point is raised, by water being evaporated which might
be drained off; consequently, the want of drainage renders the air
both colder and more liable to the formation of dew and mists, and
its dampness affects comfort even more than its temperature. It is
easy, then, to understand how local climate is so much affected by
surplus moisture, and so remarkably improved by drainage. A farmer
being asked the effect on temperature of some new drainage works;
replied, that all he knew was, that before the drainage he could
never go out at night without a great coat, and that now he could,
so that he considered it made the difference of a great coat to
him."

_Drainage increases the coldness of the subsoil in Winter._ Whether this
is a gain or loss to the agriculturist, is not for us to determine. The
object of our labor is, to lay the whole subject fairly before the
reader, and not to extol drainage as the